> From my understanding Beckhoff is very open regarding the master (who > even does not need a special hardware, > when driven by an RTOS) and are very restrictive when it comes to the >slave (where a ASIC / FPGA is needed in any case)
This was also my understanding when I read the licensing requirements. Heck they said they would even share source code with you if you were building a master... I have posted on the ethercat section of the forum calling for technical guys to get this done https://forum.linuxcnc.org/ethercat/45239-lets-get-ethercat-into-the-linuxcnc-distribution-need-technical-people-to-help Please send me an email at ether...@vmn.com.au if you can help with the tech stuff. Rod Webster *1300 896 832* +61 435 765 611 Vehicle Modifications Network www.vehiclemods.net.au On Tue, 1 Mar 2022 at 21:12, Rainer Stelzer <r.stel...@sgs-robotics.de> wrote: > Hi Gene, > > So once you've bought the controller, there is no other restriction. And > > I assume that royalty is 2x per axis, once for each end of the cable. > > No, they don't charge twice. > Part of marketing a Fieldbus-System is to make it widely accepted in the > industry, so Beckhoff > (and others like Siemens with Profinet) has/have to find a balance > between protection and easy/low cost accessibility. > > From my understanding Beckhoff is very open regarding the master (who > even does not need a special hardware, > when driven by an RTOS) and are very restrictive when it comes to the > slave (where a ASIC / FPGA is needed in any case) > > Makes also sense from commercial point of view, because in a typical > system there are much more slaves needed that masters. > > > Or can one receiver handle more than 1 axis with acceptable latency? > > A slave in EtherCat's daisy chain topology has an input and an output > Interface. (the biggest difference to most other ethernet based > fieldbusses) > > The incoming stream is shifted out with 1 bit delay to the output. > > At 100Mbit/s -> 10ns delay added up to each slave in the chain. > > The difference between one slave 3axis servo pack and three single axis > servo amps is ~20ns. > But to synchronise the output, all slaves have to wait for the full > frame received. > > Even on a 10 axis system this does not even come close to the total > frame time. > Not to mention the jitter caused by a (soft)RTOS > > > cheers > > Rainer > > > > > _______________________________________________ > Emc-developers mailing list > Emc-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-developers > _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
